Vehicles, such as a recreational vehicle or semi-trailer, incorporate jacks to support, level, or raise the vehicle. These jacks are used as leveling legs, stabilizing legs or landing gear, and include at least one extendible member that is telescopically driven to engage the ground. The extendible member telescopes from a static member fixed to the vehicle, such as by welding, bolting, and the like, at a predetermined height above the ground.
In order to account for variations in the dimensions of different vehicles and to protect both the vehicle and the jack from damage during transportation, the jack can be designed to pivot into a retracted or stowed configuration. However, while the ability to stow the jack can provide a benefit during transportation, the ability of it to swing makes it necessary to secure the jack in the deployed position. This has previously typically been done by a second hydraulic cylinder or other means, for a hydraulically powered jack. Even then, however, a force tending to move the vehicle fore or aft when it is supported by the jacks can cause the jacks to pivot and the vehicle to consequently “fall off” the jacks, with the jacks pivoting either forward or backward and the RV falling onto its suspension.
Accordingly, a need exists for a swing-down adjustable height jack for a vehicle that has an increased stability in the deployed position.